The present document primarily relates to a method of detecting an impending tip over of a vehicle, to a sensor system for detecting an impending tip over of a vehicle and to a vehicle including the sensor system. The system and method described in this document may find application in off-highway vehicles such as boom handlers or forklift trucks, for example.
It is known to estimate the position of the center of mass (CoM) of a vehicle such as a telescopic boom handler by monitoring the forces acting on the wheels of the vehicle. To this end, strain gauges may be positioned on one or more vehicle axles to detect the deformation of a vehicle axle. This deformation may be indicative of an impending tip over of the vehicle. If an impending tip over of the vehicle is detected, a warning signal may be triggered or an input command entered by an operator of the vehicle may be overwritten to prevent the vehicle from tipping over.
For example, U.S. Pat. No. 6,985,795B2 relates to a material handler with a telescopic boom that includes a frame, first and second front wheels, first and second rear wheels, and a control system. The front and rear wheels define a generally horizontal plane. The control system determines the center of gravity of the material handler and displays the location of the center of gravity of the material handler within the plane. The system includes a strain gauge mounted to a lower king pin adjacent to a vehicle wheel such that when a force is applied to the adjacent wheel the strain gauge is capable of generating a corresponding signal from stresses transferred to the lower king pin. The control system may prevent the extension of the telescopic boom if the material handler is in danger of tipping over.
However, the accuracy of CoM position estimates through deformation measurements is often impaired by a number of factors. These may include vehicle dynamics and road conditions, for example. As a result, a deformation caused for example by traction forces during normal vehicle operation may be erroneously identified as an impending tip over. Such false positives during tip over detection may compromise usability of the detection system. For example, the operator may be prevented from performing an operation in a situation where the vehicle is in a stable condition and in no danger of tipping over.